/**
 * Copyright (c) 2011-2013, kidzhou 周磊 (zhouleib1412@gmail.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.jfinal.ext.plugin.redis;

public class TopicNest {
    private static final String COLON = ":";
    private StringBuilder sb;
    private String key;

    public TopicNest(String key) {
        this.key = key;
    }

    public String key() {
        prefix();
        String generatedKey = sb.toString();
        generatedKey = generatedKey.substring(0, generatedKey.length() - 1);
        sb = null;
        return generatedKey;
    }

    private void prefix() {
        if (sb == null) {
            sb = new StringBuilder();
            sb.append(key);
            sb.append(COLON);
        }
    }

    public TopicNest cat(int id) {
        prefix();
        sb.append(id);
        sb.append(COLON);
        return this;
    }

    public TopicNest cat(String field) {
        prefix();
        sb.append(field);
        sb.append(COLON);
        return this;
    }
}
